1. Field of Invention
This invention relates to labels which are designed so that information printed thereon is protected from inadvertent removal after the label has been applied to a package. More specifically, the invention relates to labels having a plurality of tear paths incorporated therein which prevent the removal of large portions of the label when any part of the label becomes snagged, caught or stuck to another object.
2. Description of the Prior Art
Labels are used for many diverse functions. Product labels are attached to a large variety of consumer goods. Such labels typically identify the manufacturer or the distributor of the item, relevant data such as materials used to manufacture the item, its size, and its price. Descriptive labels are frequently attached to closed shipping containers so that the contents thereof may be ascertained without opening the container. Identification labels are used by all major airlines to identify checked baggage. Shipping labels are widely used by freight carriers such as the U.S. Postal Service, Federal Express, United Parcel Service. Such labels typically specify the shipper, the recipient, package contents, the shipping date, the shipping office, a tracking number and other information used during the shipping and delivery process.
When a label is used to designate the origin, destination and contents of a shipped package, there is typically no redundancy of information on the package. Thus if the label is removed before final delivery, the package will lack sufficient information to guarantee a successful delivery. Even if the package is opened, generally little or no additional information is found inside of the package which can assist in the delivery or return of the package. Moreover, the process of opening each package that has lost its label is time intensive and financially burdensome. For this very reason, many packages become unidentifiable and undeliverable during the shipping process. The major freight carriers have entire warehouses dedicated to the storage of undeliverable packages. Although every reasonable attempt is made to determine the shipper or the intended recipient, much of this undeliverable merchandise is eventually disposed of by the freight carriers through auctions or distress sales.
Several decades ago, sodium silicate (a water-soluble compound) was commonly used to apply paper labels to paperboard containers. It is still used in the manufacture of corrugated paperboard containers as an interlayer adhesive. The advantage of using sodium silicate as an adhesive is that once the moisture has evaporated from the solution, the label essentially becomes an integral part of the paperboard container. The disadvantages of using sodium silicate as an adhesive for labels is that the sodium silicate must be applied as an aqueous solution. Until the solution has dried, the label is easily removed. In addition, both the sodium silicate solution and an applicator for the solution must be available when the label is applied.
Today, sodium silicate is seldom used as a label adhesive. Modern labels are generally fabricated from a laminar sheet of printable material such as paper or a polymeric “plastic” compound. Shipping information is typically printed in human readable form, in machine-readable form, or in both forms on a top surface of the laminar sheet. The bottom surface of the label is typically coated with a layer of pressure-sensitive adhesive. Most pressure-sensitive adhesives in use today are manufactured from synthetic rubbers and other synthetic polymers. There are several advantages and several disadvantages related to the use of pressure-sensitive labels. The advantages are that they are easily applied, not only to paperboard containers, but to unpackaged plastic, rubber, and metal items as well. In addition, no messy solution or special applicators are required of to adhere the various layers to one another. The first disadvantage of pressure-sensitive adhesives is their temperature sensitivity. Pressure-sensitive labels are best attached at high temperatures and shipped at low temperatures. The higher the temperature, easier it is to both apply and remove a label having a backing of pressure-sensitive adhesive. The most significant disadvantage of pressure-sensitive adhesives is that the adhesive never sets up. In other words, it is permanently sticky. Improper application of a label to a shipped item can become a real problem. If the label is not completely adhered to the shipped item, an unadhered portion of the label can be bent away from the item and attach itself to anything with which it comes in contact, including conveyor systems, delivery vehicles, delivery personnel, and even the labels of other packages. In warm weather, the entire label could easily be removed from the shipped item or package. If the label is damaged or removed from the package during transit, proper delivery is hindered and perhaps becomes impossible.
A label is subjected to various situations that may damage the label, render it unreadable, tear a portion of the label off the package and/or tear the entire label from the package. Additionally, many shear forces are applied against the label throughout the label's shipping process. Some of these shear forces will commence as a force perpendicular to the label that becomes an angular force before the force terminates. Other shear forces may be applied because a portion of the label becomes adhered to a stationary item such as a part of the conveyor belt along the shipping pathway. This latter situation may also involve the adhesion of the label of one package to another package. Whether the label is torn away from the package or the label is torn apart will largely be determined by the action that requires the least energy. The action which occurs is the action that exerted the least resistance relative to the shear force and the label against which it was applied.
In an attempt to prevent accidental damage or loss of the label, labels have heretofore been constructed of a uniformly thick, tear-resistant impermeable polymeric film. A label constructed in such a manner may be durable and tear resistant, but presents two additional concerns. First, these labels inadvertently facilitate the complete removal of the label from the package. This undesirable result is thought to occur because, where a particular shear force applied against a weaker label might simply tear it, the same shear three, when applied against a label made of stronger, more uniform material, will remove the entire label from the shipped item or package. Secondly, because the label is an impermeable solid sheet, pockets of air may be trapped between the label and the package during its application to the package. The air prevents the complete adhesion of the label to the package, rendering its removal easier than if the label were completely adhered to the package.
Several shipping label styles of the prior art have enclosed the shipping label in a plastic envelope or pocket which is attached to the package, to prevent damage to the label during shipping. However, though this approach may protect the label from damage, it also serves to facilitate the complete removal of the envelope or pocket, along with the intact, undamaged shipping label, from the package.
An additional style of label in the prior art increased the surface area of the label, including an increase, in the area of the pressure sensitive adhesive layer. Apparently, it was perceived that through the increase in the surface area of the adhesive layer, that stronger adhesion of the label to the package would be accomplished and, thus, it would be more difficult to remove any portion of the label. However, a natural consequence of the increased surface area of the label is the increase in the volume of air that must be displaced by the label in order to accomplish adhesion to the package. The increased surface area of the label often resulted in decreased adhesion of the label because of the trapped air between the label and the package, which prevented complete adhesion of the label. Instead of providing a label that resisted inadvertent removal, the label was often more easily removed.
Accordingly, there is a need in the art for a label that adheres more tenaciously to the package, minimizes the trapping of air between it and the package during application, and which permits the tearing away of tiny bits of the label which may become snagged during shipment, thereby leaving the remainder of the label intact.